5.6. Supernova

5.6.1. Overview

This filter creates a big star reminding a super-nova. It works with
RGB and GRAY images. Light effect decreases according to 1/r where r
is the distance from star center.

5.6.2. Activate the filter

This filter is found in the image window menu under
Filters → Light and Shadow → Supernova.

5.6.3. Parameter Settings

Figure 16.107. “Supernova” filter options

Preview

If checked, parameter setting results are interactively displayed
in preview. Scroll bars allow you to move around the image.

Center of Nova

X, Y

You can use input boxes to set horizontal (X) and vertical
(Y) coordinates of SuperNova center. You can also click the
SuperNova center in the preview box.

Tip

To center Supernova precisely, select
“percent” option in the Unit dropdown list
and fix X and Y to 50%.

Show position

This option brings up a reticle in preview, centered on the
SuperNova.

Color

When you click on the color swatch, you bring up the usual color
selector.

Radius

This is radius of the SuperNova center (1-100). When you
increase the value, you increase the number of central white
pixels according to r*r (1, 4, 9...).

Spikes

This is number of rays (1-1024). Each pixel in the nova center
emit one pixel wide rays. All these rays are more or less
superimposed resulting in this glittering effect you get when
you move this slider.

Random hue

Color rays at random. (0-360) value seems to be a range in
HSV color circle.